Compressor utilizing low volt power tapped from high volt power

ABSTRACT

Low voltage electrical power is supplied to a diagnostic control device in a sealed compressor. Electrical power is tapped from a high voltage power line and transformed to low voltage power that in turn operates the diagnostic control device. The diagnostic control device and the electric voltage transforming system are housed within the sealed compressor shell, thus eliminating the need for additional openings in the compressor shell. Other low voltage devices can be powered in this way.

BACKGROUND OF THE INVENTION

[0001] This invention relates to a system provided within the shell orsealed housing of a compressor for converting high voltage electricpower from a single power source to low voltage electric power forpowering the auxiliary compressor systems, such as a diagnostic controldevice.

[0002] Compressors are utilized to compress a refrigerant as part of arefrigerant cycle in cooling systems. Modern compressors for refrigerantcompression are typically enclosed within a sealed housing. Typicallycompressors are driven by an electric motor which receives high voltageelectric power from an outside electrical power source by way of a powerline extending through an opening in the sealed housing. It is essentialthat all openings through the sealed housing are well sealed to preventleakage.

[0003] Refrigerant compressors operate under extreme conditions and mayhave relatively complex operational components. Compressor operationpresents many design challenges. In addition to the potential forleakage as mentioned above, there is the potential for a variety ofoperational faults to occur during use as well as during startup andshutdown. For example, an overcharge or undercharge of refrigerant canhinder compressor performance. An improperly wired compressor can alsoresult in compression malfunction.

[0004] Typically, compressors have been provided with a plurality ofprotection devices that sense various performance properties ofessential compressor components as compared to predetermined values. Theprotection devices then respond accordingly in a predetermined manner.For example, the electric motor used for driving a compressor pump istypically provided with a protection switch, which is actuated if apredetermined temperature is reached at which point the motor isstopped. Also, condition responsive valves have been proposed in sealedcompressors.

[0005] The inventors of this application have recently proposed sensingvarious performance properties of essential compressor components usinga singular diagnostic control device. The diagnostic control device,which is preferably microprocessor based, receives signals relating to anumber of operational factors in a compressor. The diagnostic controldevice is disclosed in co-pending application Ser. No. ______, filed______, entitled “Compressor Diagnostic System”.

[0006] Typically, the compressor elements are driven by an electricmotor. The electric motor is housed within the compressor shell and ispowered by a high voltage source originating at a point outside thecompressor shell by way of a power line received through an inletopening in the compressor shell.

[0007] The microprocessor based diagnostic control device operates usingrelatively low voltage electric power as compared to the relatively highvoltage electric power required to power the electric motor of thecompressor. The same is true for the above-mentioned sensors, etc.

[0008] Thus, it would be desirable for a low voltage device, such asdiagnostic control device, a sensor, etc. to make use of the existingelectric power supply that powers the electric motor of the compressor.Thus, the low voltage device can be positioned within the compressorshell without requiring additional low volt wiring to be fed through anyadditional openings in the sealed compressor shell.

SUMMARY OF THE INVENTION

[0009] In the disclosed embodiment of this invention a refrigerantcompression system is provided with an electronic circuit to feed lowvoltage electrical power to a diagnostic control device. The diagnosticcontrol device is positioned within the sealed housing, of thecompressor and operates using low volt electrical power. The low voltelectrical power required to operate the diagnostic control device isobtained from an existing high volt electric power source that is usedto power the motor of the compressor.

[0010] The compressor shell is provided with an inlet opening throughwhich a high volt power line extends. The high volt power line extendsfrom a high voltage electric power source positioned outside of thesealed compressor shell. Within the compressor shell, the electric powerused to operate the diagnostic control device is tapped from theexisting high voltage incoming power line, and then converted to therequired low volt electric power. The power is converted using a knownconversion circuit preferably including a transformer.

[0011] The diagnostic control device is powered with the desired lowvolt electric power using the existing high volt power line. Thus, thenecessity to feed additional low volt wiring through any additionalinlet openings in the compressor shell is eliminated.

[0012] While the invention is disclosed for powering a diagnosticcontrol device, other low voltage devices such as sensors, etc. can alsobe powered in this fashion.

[0013] These and other features of the present invention can be bestunderstood from the following specification and drawing, the followingof which is a brief description.

BRIEF DESCRIPTION OF THE DRAWING

[0014]FIG. 1 is a schematic view of a portion of a sealed compressorthat incorporates a system to feed low voltage electrical power to adiagnostic control device.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

[0015] A sealed compressor 10 is illustrated generally and schematicallyin FIG. 1. It should be understood that compressor 10 is preferablyincorporated into a refrigerant cycle, such as that typically found inair conditioning or other cooling or heating cycles.

[0016] A compressor pump unit, as that typically utilized in a scrolltype compressor, is schematically shown at 12. The scroll compressorpump unit 12 is driven by electric motor 14. Electric motor 14 ispowered by a high voltage outside power source 16. The power source maybe three phase, or single phase. Compressor pump unit 12 and electricmotor 14 are housed in sealed compressor shell 18. The high voltageelectric power from outside power source 16 is fed to motor 14 by way ofincoming power line 20 which enters compressor shell 18 through inletopening 22.

[0017] A diagnostic control device 24 is provided at a location withinthe compressor shell 18. Diagnostic control device 24 can monitor avariety of operational conditions of the compressor 10 during use. Thedetails of the control device are as disclosed in co-pendingapplication, Ser. No. ______, filed ______ and entitled “CompressorDiagnostic System”. Diagnostic control device 24 requires a relativelylow volt electrical power supply in order to operate. Electrical poweris tapped from incoming power line 20 at a power tap and converted tothe required lower voltage electrical power by way of conversion circuit27 which include a transformer and appropriate circuit safetycomponents. A worker in the electrical arts could provide an appropriateconversion circuit. The lower voltage electrical power is then suppliedto diagnostic control device 24 by way of power feed line 28.

[0018] The diagnostic control device 24 operates using power from theexisting incoming power line 20, thus eliminating the need foradditional low volt wiring to be fed through any additional openings inthe compressor shell 18.

[0019] A sensor 40 is also shown schematically and controls anelectronically operated valve 42. Devices 40 and 42 both operate usinglow voltage and receive power from conversion circuit 27. The devices24, 40 and 42 can be used individually, or in combination. If more thanone device is powered by circuit 27, an appropriate routing circuit maybe used. It should be understood the devices 40 and 42 may be as known,and form no portion of this invention.

[0020] A preferred embodiment of this invention has been disclosed,however, a worker in this art would recognize that certain modificationswould come within the scope of this invention. For that reason, thefollowing claims should be studied to determine the true scope andcontent of this invention.

What is claimed is:
 1. A compressor comprising: a sealed compressorshell housing a compressor pump unit, an electric motor for driving saidcompressor pump unit, and a low voltage device for monitoringpredetermined aspects of compressor performance; an inlet opening insaid compressor shell for receiving an incoming high volt electric powersupply for powering said electric motor; and a system for convertingsaid incoming high voltage electric power to a low volt electric power,and feeding low volt electric power to said low voltage device.
 2. Acompressor as recited in claim, 1 wherein said system for converting tolow volt electric power is housed within said sealed compressor shell.3. A compressor as recited in claim 2, wherein said system forconverting low volt electric power has a power tap associated with saidincoming high volt electric power supply; and a circuit for convertinghigh volt electric power to low volt electric power;
 4. A compressor asrecited in claim 3, wherein said circuit for converting high voltelectric power to low volt electric power includes a transformer.
 5. Acompressor as recited in claim 1, wherein said compressor pump unit is ascroll compressor.
 6. A compressor as recited in claim 1, wherein saidlow voltage device is a diagnostic control.
 7. A compressor as recitedin claim 1, wherein said low voltage device is a sensor.
 8. A compressoras recited in claim 1, wherein said low voltage device is a valve.
 9. Amethod for providing low voltage electric power to a low voltage devicethat is housed within a sealed compressor shell comprising the steps of:tapping high voltage electrical power from an incoming high voltageelectric power line positioned within said sealed compressor shell;converting said high voltage electric power to low voltage electricpower; and feeding said low voltage electric power to said low voltagedevice.
 10. A compressor comprising: a sealed compressor shell housing acompressor pump unit, an electric motor for driving said compressor pumpunit, a diagnostic control device for monitoring predetermined aspectsof compressor performance, and a conversion circuit for feeding low voltelectric power to said diagnostic control device; an inlet opening insaid compressor shell for receiving an incoming high volt electric powersupply for powering said electric motor; and said circuit for feedinglow volt electric power to said diagnostic control device comprises apower tap associated with said incoming high volt electric power supply,and a system for converting high volt electric power to low voltelectric power for powering said diagnostic control device.
 11. Acompressor as recited in claim 10, wherein said circuit for convertinghigh volt electric power to low volt electric power includes atransformer.